ISSN:0001-1541    

DOI:10.1002/aic.690040102

出版商:American Institute of Chemical Engineers    

年代:1958

数据来源: WILEY

摘要:

AbstractA method is presented for predicting the effect of allowance for radiation exchange on the distribution of temperature and heat transfer within a furnace chamber. The system is divided into surface zones and gas zones, the number being dependent on the desired accuracy of the result. Direct‐exchange factors are available for gas‐gas, gas‐surface, and surface‐surface zone interchange. From these factors one can determine the net exchange factor for any zone pair, making due allowance for interaction with all other zones. The resultant factors are then fed into a set of energy balances, one on each zone, which by simultaneous solution permit a determination of the space distribution of gas and surface temperatures and the distribution of heat flux over the s

ISSN:0001-1541    

DOI:10.1002/aic.690040103

出版商:American Institute of Chemical Engineers    

年代:1958

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690040123

出版商:American Institute of Chemical Engineers    

年代:1958

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690040121

出版商:American Institute of Chemical Engineers    

年代:1958

数据来源: WILEY

ISSN:0001-1541    

DOI:10.1002/aic.690040122

出版商:American Institute of Chemical Engineers    

年代:1958

数据来源: WILEY

摘要:

AbstractA broad empirical study of nine independent sets of data on fluidized‐bed heat transfer is presented, with correlation of the data in two groups. A wide range of the many variables is covered, and some data on commercial units are included. Data for external (i.e., walls of the fluidizing vessel) and internal (i.e., tubes in the bed) heat transfer surfaces are correlated graphically. The correlations indicate the importance of heat transport by the mobile particles and of unsteady state conduction in the ga

ISSN:0001-1541    

DOI:10.1002/aic.690040104

出版商:American Institute of Chemical Engineers    

年代:1958

数据来源: WILEY

摘要:

AbstractConditions for the incomplete displacement of gas from the valley between two parallel ridges by a liquid‐drop front advancing over the ridges are calculated. The significant parameters are found to be the liquid density, surface tension, contact angle, and geometry of the ridges. The solution may be obtained analytically or, more conveniently, graphically. Surface roughnesses are divided into four classes, one of which can stably switch from liquid—to gas—fill, and another vice versa. This may account for some of the hysteresis effects reported in bubble nucleation. It is pointed out that surfaces consisting predominately of cavities are more likely to follow these considerations than grooved surfaces, owing to displacement of gas by advance of liquid along the grooves. An example important in boiling and cavitation theory is worked out, and qualitative agreement with the literature is

ISSN:0001-1541    

DOI:10.1002/aic.690040105

出版商:American Institute of Chemical Engineers    

年代:1958

数据来源: WILEY

摘要:

AbstractProfiles of eddy viscosity and Prandtl mixing length in fluids flowing steadily and isothermally in smooth tubes have been calculated from the velocity data of several investigators for Reynolds numbers between 1.2 × 103and 3.2 × 106. In the transition range unusually high values of eddy viscosity and mixing length are obtained in some portions of the stream. In the fully turbulent range the effect of Reynolds number is small and the mixing length tends toward zero at the center of the tube. The parameters for turbulent flow between parallel plates have been correlated through the concept of an equivalent tube. The results are of importance in designing equipment for heat and mass transfer and mixin

ISSN:0001-1541    

DOI:10.1002/aic.690040106

出版商:American Institute of Chemical Engineers    

年代:1958

数据来源: WILEY

摘要:

AbstractThe coolant flow distribution among parallel passages in a nuclear reactor (or boiler or heat exchanger) can be very sensitive to variations in heat input, channel dimensions, etc. In a previous paper this flow sensitivity was defined in terms of certain partial derivatives, which were related by analytical expressions to fluid properties and operating characteristics. Flow sensitivity contributes largely to potential malfunction, reduced efficiency, or failures. The use of valves and orifices was quantitatively evaluated for supercritical water in the earlier paper. The scope of this paper is to consider the utility of mixing headers. These mixing chambers are located along the flow passage as a common receiver for parallel flow from many channels. The headers, in turn, supply subsequent lengths of heated passages in parallel. Analytical expressions are derived for the effect of headers on flow, outlet‐fluid enthalpy, and channel‐wall temperatures. The limiting cases of minimum and complete mixing in the headers are considered and numerical results for water at supercritical pressures are given to show the marked increase in stability obtained by use of intermediate mixing head

ISSN:0001-1541    

DOI:10.1002/aic.690040107

出版商:American Institute of Chemical Engineers    

年代:1958

数据来源: WILEY

摘要:

AbstractLocal rates of convective heat transfer from air at high temperature to a cold wall were measured in the inlet region of a circular tube. Air entered the tube with a flat velocity and temperature profile at temperatures from 480° to 2,000°F. and flow rates corresponding to Reynolds numbers from 4,500 to 22,500. The inner surface of the 1.0‐in. I.D. tube was maintained at approximately 100°F. by water cooling. Local rates of heat transfer were determined at 1.5, 4, 7, and 10 tube diameters from the entrance by measuring the radial temperature profile in thermally isolated, annular sections of the tube wall.The local rate data for all gas temperatures are well represented by previous correlations for small temperature differences if the gas properties are evaluated at the bulk temperature rather than at the film temperature. The data agree well with the data of previous investigators wherever the experimental ranges ove

ISSN:0001-1541    

DOI:10.1002/aic.690040108

出版商:American Institute of Chemical Engineers    

年代:1958

数据来源: WILEY